Vapor electric converter



Aug. 11, 1936. J. SLEPIAN 2,050,390

VAPOR ELECTRIC CONVERTER Filed July 16, 1935 2 Sheets-Sheet L M I I WITNESSES: INVENTOR- N Jase 0h 5/50/04 M P g ATTORN EY J. SLEPIAN VAPOR ELECTRI C CONVERTER Filed July 16, 1935 'illllllHF' 2 Sheets-Sheet 2 WITNESSES:

7 INVENTOR fafepb 5430/00.

ATTORNEY i atentecl Aug. 11, 1936 UNITED STATES PATENT OFF-ICE Westinghouse Electric & Manufacturing Company, East Pittsburgh, 3a., a corporation of Pennsylvania Application July 16, 1935, Serial No. 31,591

Claims.

My invention relates to a vapor electric converter andparticularly to anexcitation system and a make-alive type converter.

In the application of make alive'type convert- 5 ers, it has been customary to-useusuitable auxiliary valves usually of the hot-cathode type'to supply make-alive currentrfrom the'main anode of the converter valve to the make-alive electrode. Inv application, these auxiliary valves are called upon todeliver: relatively short current impulses of considerable magnitude. .Theseirelatively high current impulses have proven unexe pectedly detrimental to the auxiliary valves so that the replacement of these auxiliary valves has proven a major item of upkeep expense for the converters. It is,.therefore,: an object'of my invention to provide a make-alive system utilizing auxiliary valves of thetypewhich-are sufficiently rugged to withstand the necessary current impulses, and thereby reduce the upkeep cost of such converters.

In the construction according to my invention, the heretofore usual hot-cathode auxiliary valves are replaced by a suitable vapor-electric device of sufficient size and current capacity to supply the necessary make-alive current. These auxiliary valves may all be grouped in a single auxiliary converter. The make-alive electrodes are then energized by means'of an auxiliary impulse transformer responsive to;the currentfl flow in the auxiliary valves.

Preferably, the auxiliary valves are directly connected to the anodes of the make-alivev valves, but, if desired, they. may be supplied with current from any suitable source. I

Also, Ihave found that the auxiliary valves may conveniently beincorporated as auxiliary 40 anodes, in the make-alive converters. :When this is done, the auxiliary anode for any givenvalve is inserted in another make-alive valve, which is normally excited at the time when the anode of thev valve being excited becomes positive. In 45 this manner, the auxiliaryvalve will be in a tube which is excited at the instant it is desired to ex cite the next succeeding valve. Suitable grid control may be supplied for the auxiliary valves to delay the excitation or the make-alive elec- 50 trode until the anode of the mainvalve' being excited as become sufiiciently positive. to guarantee striking of the conversion arc therein.

Other objects and advantages. of myinvention 55 willbe apparentfrom a detailed description when taken in conjunction with the accompanying drawings, in which:

Figure-1 is a schematic illustrationof a converter embodying my invention; and

Fig. 2 is a similar-view of a modification showing the auxiliary anodes placed in the make-alive type valves.

Theapparatus according to my invention comprises an alternating-current circuit l and a diroot-current circuitii2 connected by means. of a 10 valve. make-alive type converter 3 and :a suitable transformer 54 for controllingthe operationof the valves 5 of the converter 3. Each of the valves.5 of .the converter .3 comprises a main anode 6 and acathode l with a make-alive type 15 electrode 8; that .is, an electrode having astem 9 of conducting material and a terminal ID of semi-conducting material making ,positive and permanent contact with the cathode! under all normal operating conditions.

Connected in parallel with the anode 6 and cathode! .of the. main converter valve 5 is an auxiliary valve I5 for providing excitation current toxthe make-alive electrode 8. This auxiliary valve I5 is connected in series with the primarywinding N5 of a suitablemake-alive-transformer H, the secondary l8 ofrwhich isconnectedto. the make-aliveelectrode't and to the cathode lwof j the mainvalve 5. Consequently, when current flows through the auxiliary valve I5, 30 the current flow energizes the make-alive transformer. I'ltandasupplies a current impulse to the makeaaliveelectrode I, which. in turn creates a cathodespot in the make-alive valve.5, and permits the vformation of a current-carrying are 35 therein.

The auxiliaryv valves l 5*.1orv supplying current to the make-alive electrodes 1 are preferably placedeinra constantly excited device, and, if desired, they may,-as shown,-.all be placed in a sin- 40 gle auxiliary vapor. arcrectifierlll. The auxiliary valves I 5' are preferablyvprovided with a suitable resistor; 2| and reactor 22 for controlling the current therethroug-h,.said 'reactance.22 and resistance 2| being sufficientto cause the discontinuance of the auxiliary. arc-after thestriking oi the-arc in the main converter valve 15.

Preferably, the auxiliary valves l5 are provided with suitable control :grids 25, so that current will notbeallowed to flow. therein. untilsuch time as the potential of the main anode Bis sufilciently positive to guarantee striking :ofthemain are when the cathode spot is created-by the makealiveelectrode 8. Also, thiscontrol grid;i25 may be'utilized for delaying the-creation of the. cathode spot until any desired instant in the positive or normally conducting half cycle, whereby the voltage and current output of the converter 3 may be regulated.

Since the currents in the make-alive transformer I! are unidirectional in character, there is a tendency for the cores 26 of the transformers IT to become saturated. This may be overcome by special construction of the transformer core, or by combining two or more make-alive transformers I 1 on the same core and so adjusting the windings of the separate transformers I! that the successive energization of these transformers reverses the residual flux in the transformer core 26.

In the operation of the converter according to my invention, the device is put in operation by first exciting and then maintaining the excitation of the auxiliary rectifier 20. Then by the application of potential to the transformer 4, positive potential will be applied to at least one of the main anodes 6 of the converter 3, which positive potential is also applied to the parallel connected auxiliary valve l5, and if the control grid of this auxiliary valve is released, an arc will strike in the auxiliary valve l5 and the current fiow through the valve l5 energizes the make-alive transformer I! which produces a cathode spot in the corresponding main converter valve 5. Upon the pickup of the converter arc in this valve 5, the reactance 22 and resistance 2| in series with the auxiliary valve l5 concludes current flow therein and stops the current application to the make-alive electrode 8, so that after the termination of the normal conducting arc therein, there will be no excitation until the main anode again becomes positive.

Control impulses may be supplied to the electrodes for the auxiliary valves l5 from any suitable source, such as a grid-control transformer 30. If desired, this transformer may be provided with a phase shift in the form of an induction regulator 3|, the primary 32 of which is connected to a suitable source of supply, such as the alternating-current circuit I, and the secondary 33 of which is connected to the primary of the control transformer 30.

In the modification according to Fig. 2, each of the main make-alive valves 35 is provided with an auxiliary electrode 36 connected through the primary 3? of a suitable make-alive transformer to the anode 6 of the next succeeding valve 35. Consequently, when the anode 6 in the next succeeding valve 35 becomes positive, the auxiliary anode 36 will strike to the cathode 1 of the preceding valve 35, which is still excited because of the fiow of converter current therein. The flow of current to this auxiliary anode 36 energizes the secondary 38 of the make-alive transformer, and supplies a current impulse to the make-alive electrode 8 which then creates a cathode spot and excites the succeeding valve 35. If desired, suitable control grids 4| may be applied to the auxiliary anodes 36 so that the cathode spot will not be created before there is suificient positive potential on the main anode 6 to permit pick-up of the current-carrying arc in the excited valve 35.

Any one of the make-alive transformers may be provided with a suitable device such as an auxiliary valve 39 and switch 40 to procure an original current impulse to make-alive electrode when the device is being first energized.

To start the device in operation, the switch 40 is closed, then, when the anode 6 connected thereto becomes positive, the valve 39 permits current flow in the primary 3'! of the make-alive transformer and supplies current to the makealive electrode 8 associated therewith and permits pick up of the arc in the make-alive valve 35, after which the switch 40 is opened.

Once put in operation, the converter continues automatically and, as each succeeding valve becomes positive, the auxiliary anode therefor and associated with the preceding valve becomes operative and supplies current to the make-alive of the succeeding valve.

For purposes of illustration, I have shown specific embodiments of my invention; however, it will be apparent to those skilled in the art that many changes may be made therein without departing from the true spirit of my invention or the scope of the appended claims.

I claim as my invention:

1. A vapor-electric converter comprising a plurality of valves connected for successive operation, each of said valves having a main anode and a cathode of vaporizable reconstructing material, a make-alive electrode in permanent contact with said cathode, and means for intermittently causing current flow in said make-alive electrode comprising an auxiliary anode in another of said valves and connected to the anode of the valve being excited and a transformer energized by current flow to said auxiliary electrode.

2. A vapor-electric converter comprising a plurality of valves connected for successive operation, each of said valves having a main anode and a. cathode of vaporizable reconstructing material, a make-alive electrode in permanent contact with said cathode, means for intermittently causing current flow in said make-alive electrode comprising an auxiliary anode in another of said valves and connected to the anode of the valve being excited and a transformer energized by current flow to said auxiliary electrode, and means connected to one of said transformers for initiating operation of said converter.

3. A vapor-electric converter comprising an evacuated valve chamber, an anode and a cathode in spaced relation in said chamber, a control electrode having a conducting stem and a tip of semiconducting material in permanent contact with said cathode, an auxiliary anode connected to the first-mentioned anode, said auxiliary anode being in a separate discharge device, said separate discharge devices being excited at the time the anode becomes positive, a transformer having a primary winding connected in series with said auxiliary anode and a secondary winding connected between the conducting stem of the control electrode and said cathode.

4. A vapor-electric converter comprising an evacuated valve chamber, an anode and a cathode in spaced relation in said chamber, a 'control electrode having a conducting stem and a tip of semi conducting material in permanent contact with said cathode, an auxiliary anode connected to the first-mentioned anode, said auxiliary anode being in a separate discharge device, said separate discharge devices being excited at the time the anode becomes positive, a transformer having a primary winding connected in series with said auxiliary anode and a secondary winding connected between the conducting stem of the control electrode and said cathode, a control grid associated with said auxiliary anode and means for impressing control potential thereon.

5. An electric conversion system comprising an alternating-current circuit, a direct-current cirwit, a plurality of make-alive type valves for transferring energy between said circuits, transformer means for connecting said valves to both of said circuits, each of said valves comprising two principal electrodes, a make-alive electrode cooperating with one of said principal electrodes to create a cathode spot thereon, said valves being so connected to said transformer that the valves are successively operative to transfer current be- 10 tween said circuit the potential across the succeeding valve normally becoming positive before the cessation of conduction in the last preceding valve and means for energizing the make-alive electrode of each succeeding valve comprising an auxiliary electrode in the preceding valve said auxiliary electrode being connected to the positive electrode of the succeeding valve and a transformer winding in said connection. 

